Telephonic transmitter



(No Model.) I v 2 Sheets8heet 1.-

' H. CLAY;

TELBPHONIG TRANSMITTER.- 7

No. 288,017. I Patented Nov, 6, 1883.

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A TTORNEY.

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(No Model.) v 2 sheetssheet 2.

H. OLA Y TELEPHONIG TRANSMITTER. 7 No. 288,017. Pafm11tak1 Nov, 6, 1883.

W1 TNESSES: JNVENTOR,

1am I 5 'ATTORNEY N mans, MW, Was-damn u. a

I tion.

UNITE TATES HENRY CLAY, or PHILADELPHIA, PENNSYLVANIA.

TELEPHONVIC TRANSMITTER.

SPECIFICATION. forming part of Letters l atent No. 288,017, datedNovember 6, 1883.

Application filed February-10, 1888. ("No model.)

, To all whom it may concern:

- Be it known that I, HENRY CLAY, a citizen of the United States,residing at Philadelphia,

in the county of Philadelphia and State of 5 Pennsylvania, have inventedcertain new and useful Improvements in Telephonic Transmitters, of whichthe following is a specification,

reference being had therein to the accompany.

ing drawings, wherein- Figure 1 is an elevation, partly sectional, of myinvention. Figs. 2, 3, 4, and 6 are like views of slight modificationsof same. Figs. 5 and 7 are detail perspectives, and Fig. 8 isa sectionalperspective, of a still further modifica- My invention has relation tothat class of telephonic transmitters wh erein the variations ofpressure upon a carbon block vary the resistance therein to the passageof an electric current to vary its strength in unison with thevibrations caused by vocal utterances.

My invention consists of constructions and combinations, as willhereinafter be described and claimed.

Referring to Fig. 1 of the accompanying present axial or diametricalpoints for contact with the diaphragm and its supportingpiece G. Thelatter is made of metal or other electrical conductor, and is providedwith asocket or recess, c, for retaining the ball or block B in itsnormal location upon the diaphragm: The latter and the supporting-pieceO serve as electrodes, between which the block B is inter posed. I Theelectrode G is secured to a support, E, 5 or to the sounding-box by astrip, D, which may be flexible, springy, or rigid.

F F are the wires or conductors, designedto be arranged and connected tothe diaphragm, electrode 6, battery, or primary circuit of aninduction-coil, 850., in the usual or other desired way.

The operation is obvious. As the diaphragm vibrates by speaking againstit or in its neighborhood the a block B is compressed thereby, and avarying contact is produced for varying the strength or setting upimpulses in the electric current passing therethrough, as heretofore;but as said block is round or globular in outline it presents axialpoints only for impingement with the electrodes. It is therefore morereadily compressed, and that to a greater degree, by the varyingvibrations of the diaphragm, and is more sensitively controlled therebyfor thefollowing reason: Each vibration of the diaphragm produces agreater compression. of the block B than it would otherwise do if saidblock were fiat or in the form of a disk or button and the electrodesimpinged upon the fiat surfaces thereof. Such increased compressions,therefore, correspondinglyvary the contact of the block B, andconsequently the impulses-or vibrations in the current are rendered moreacute and intensified, or they more nearly correspond with the amplitudeof the sound-waves acting upon the diaphragm. Such intensified currentvariations,when they I operate areceiver,will therefore cause the latterto reproduce audible sounds clearer and w more distinctly than hasheretofore been accomplished.

A mechanical advantage is derivedfrom the use of the ball B, which isthis: As the diaphragm vibrates the ball has an oscillating or rotatingmotion and continually presents new or fresh poles or points for contactwith the electrodes. Consequently the wear of the ball is over itsentire surface, and not in one spot, as is the case with fiatblocks nowin use.

While the above-described construction is the most simple andadvantageous form of my improvement, yet I do not confine myselfthereto, as the electrodes may be varied in position and form and theshape of the block altered or modified in various ways to present axialor diametrical points for contact with, the electrodes without departingfrom the spirit of my invention, some of which modifications I will nowproceed to describe.

In- Fig. 2 awooden diaphragm, or one of other suitable material, issubstituted for the metallic diaphragm above described, in which case ametal electrode, G, is secured thereto,

' In Fig. 4 the strips D are dispensed with and two diaphragms areemploycd,which also serve as the electrodes, one of said diaphragmsbeing formed with a central depression or socket, c, for the ball orblock. B, as is more plainly illustrated in Fig. 5; or said diaphragmmay have an'elongated depression instead of said socket, as representedin Fig. 7.

If desired, the carbon block may be formed of a disk having its edgesslightly rounded,a s shown in Fig. 6; or it may consist of a cylindricalblock, as indicated in Fig. 8, said cylinder being diametricallyarranged between the electrodes in which case one of the latter isprovided with studs or projections c c, to

keep the block in its normal position, and pre-" vent it movinglongitudinally.

It will be seen, therefore, that the block B may be varied inconfigurationand the electrodes modified in form and position, yet inall the modifications the block is loosely held between two impingingelectrodes and accomplishes the same effect as the ball.

, What I claim is 1. In a telephonic transmitter, the combination of afiat electrode, a'recessed. electrode, and an interposed ball, sphere,or cylinder presenting diametrical or polar points of contact to saidelectrodes, for the purpose set forth.

2. In a telephonic transmitter, the combination of a fiat electrode, arecessed electrode having a suitable support, and a round, spherical,-orcylindrical block located between said electrodes and presentingdiametrical contact to said electrodes.

In testimony whereofI affix my signature in presence of two witnesses.

HENRY LAY.

\Vitnesses: S. J .VAN, STAVOREN, CHAS. F. VAN HORN.

